Tech vs sleep: are your devices keeping you up at night?
Last week I spoke to Sustainable Tech 4 Good about how technology impacts our sleep. We covered everything from the real impact of blue light, to how what we watch affects us, whether WiFi is actually disrupting sleep, and how tech can help us catch more Z’s.
Here's some of the highlights:
We’ve all been told that blue light damages our sleep. But why is that? And what’s the impact?
For thousands of years - the majority of time humans have been on Earth - the only time we would see bright or blue light was during the day. The sun is bright light, and the sky is blue light.
Then Thomas Edison came along in 1879 with his bright idea and invented the lightbulb. Now most people in the Western world live in light-polluted areas, and many stay on screens well into the evening, often right up until they try to sleep.
The problem is, our brain evolved for a time that doesn’t exist anymore. When it senses bright or blue light, it still thinks it’s daytime, so it makes us feel awake. Big issue if you’re trying to sleep.
It’s all based around two chemicals - cortisol and melatonin. More cortisol is released when your brain thinks it’s daytime, which makes you feel more alert and focused. Then when your brain thinks it’s evening, melatonin levels rise - a hormone that helps you fall asleep and stay asleep.
By staying around light close to bedtime, you can trick your brain into thinking it’s earlier than it is. Some studies have shown melatonin can be suppressed by up to around 85% in certain conditions, and cortisol can stay higher than it should.
People take longer to fall asleep, have lower sleep quality, and wake up more during the night after using screens right before bed. And a lot of that comes back to having lower levels of melatonin in your system.
So I’d recommend avoiding bright and blue light within 90 minutes of sleep. Put some warm lamps on, avoid screens, and sleep will come easier. I know an hour and a half isn’t realistic in some cases, so just try to do whatever you can - but the longer the better.
And are there any ways of reducing the blow? I’ve seen blue light blocking glasses advertised.
Yeah, there are definitely ways to damage control.
Blue light glasses do make an impact, but they’re nowhere near a full solution. Just a tool that can help a bit.
It’s great that they block blue light, but it’s not only blue light that suppresses melatonin. Most colours have some effect.
Blue light blockers are useful if you need to see all the colours on your screen - like if you’re doing graphic design. In that case I’d recommend orange-tinted ones, as they have a much stronger effect than clear lenses.
But if you can get away with a heavily distorted view, I’d recommend putting a red filter on your screen. It strips out most wavelengths except red, and red light has the least impact on melatonin. It may have little to no effect compared to other light. And it’s free! You can do it on laptops or phones - the easiest way is just to search how to make your screen red.
That said, even if you sort the light problem, I’d still recommend staying off screens near bedtime where possible. Because what you’re looking at matters too.
How do you mean? What type of thing could ruin it?
There are two systems in play.
The light side links to your circadian rhythm. Looking at light at the wrong times throws off your body clock, meaning it might not be ready for sleep when you want it to be.
But your nervous system plays a huge role as well. That’s your brain, spinal cord, and all your nerves. It’s constantly deciding whether you should be in a more stressed or relaxed state.
It’s always asking, “how much is being demanded of me?” The more demand, the more alert you become.
So if you’re watching something demanding - like something educational, thought-provoking, or even something intense like a video about AI taking over the world - your system stays switched on.
The more alert you are, the higher your heart rate, brain activity, and cortisol. That makes it harder to fall asleep and stay asleep. And the frustrating part is that it takes time to wind down. Even moderately engaging content can keep you wired for up to an hour. And working late has a similar effect.
So if you are on screens before bed, keep the content as undemanding as possible. Something familiar, or simple tasks that don’t require much thinking.
And is there anything else we should be wary of?
There are a couple of other things worth mentioning when it comes to tech and sleep.
There’s been a lot of noise around flickering screens. Even though we can’t consciously see it, screens rapidly switch on and off. Your brain smooths it out, but your nervous system is still processing it.
That can increase demand. Slightly.
That said, this is becoming less of an issue with newer screens. Older ones may have more of an impact, especially for people who are more sensitive.
The general recommendation is to use a screen with at least a 60Hz refresh rate, ideally higher, and one that’s marketed as flicker-free.
If you are using an older or lower-quality screen, it’s worth avoiding it in the hour before bed. But in most cases, this isn’t a major driver compared to other factors.
People also ask about WiFi and Bluetooth. As it stands, there’s no strong evidence that WiFi or Bluetooth negatively affect sleep. There are products that claim to block signals, but there’s nothing strong enough to say they’re worth buying. If they give someone peace of mind, that might help indirectly, but it’s not something most people need to worry about.
And are there ways tech can actually improve sleep?
Sleep tech is booming. The market is growing very significantly, very quickly, and there’s a reason for that.
Wearables, like smart watches, have played a big role in making sleep more talked about and better understood. The amount of data we now have on sleep is huge, and it’s helped people realise how important it is.
That said, wearables can lead to something called orthosomnia - where people become overly focused on getting perfect sleep. That can create anxiety, and even make sleep worse. There’s also the nocebo effect, where seeing a bad sleep score makes you feel more tired than you actually are. I’ve experienced both at points!
I think sleep stats are great when used with a purpose. They can help you understand patterns and track improvements. But if you’re checking them without a clear reason, it can become unhelpful.
Other than that, there are also lots of gadgets claiming to improve sleep. Some are promising, but many aren’t well backed yet, so I’d be selective.
The red light filter I mentioned before is a good hack. Otherwise one of the few things that can be genuinely useful is a 10,000 lux lamp. These mimic daylight, so using one in the morning can help you feel more alert and support your body clock. I saw one study suggesting this can improve energy levels by up to 20% during the day. Plus it helps set your body clock first thing - almost like starting a timer that makes it easier to fall asleep later on. They’re pretty cheap as well.
And white noise machines can be helpful if your environment is noisy and earplugs aren’t enough. Even if noise doesn’t fully wake you, it can keep your sleep lighter because your nervous system stays slightly alert.
A huge thank you to Charlie and Sue, at Sustainable Tech 4 Good for being so interested in the impact of tech on sleep. For anyone interested in reducing e-waste and using tech for social good, give their page a look!
Technology is absolutely brilliant. And yes, there are ways it can harm our sleep, which can then domino into our general wellbeing and performance. But by being aware of the potential side effects, we can make sure it’s harnessed for good - sustainably (pun very much intended).
As always, please don’t hesitate to get in touch if you have any questions or want to share your thoughts. I’m always incredibly excited to sleep talk!
T 💙